WO2019225425A1 - Electric oil pump - Google Patents

Electric oil pump Download PDF

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Publication number
WO2019225425A1
WO2019225425A1 PCT/JP2019/019263 JP2019019263W WO2019225425A1 WO 2019225425 A1 WO2019225425 A1 WO 2019225425A1 JP 2019019263 W JP2019019263 W JP 2019019263W WO 2019225425 A1 WO2019225425 A1 WO 2019225425A1
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WO
WIPO (PCT)
Prior art keywords
pump
motor
housing
bearing
axial
Prior art date
Application number
PCT/JP2019/019263
Other languages
French (fr)
Japanese (ja)
Inventor
卓志 松任
直嗣 北山
健児 水尻
Original Assignee
Ntn株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2018097094A priority Critical patent/JP2019203390A/en
Priority to JP2018-097094 priority
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Publication of WO2019225425A1 publication Critical patent/WO2019225425A1/en

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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C15/00Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00Rotary-piston machines or pumps
    • F04C2/08Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/10Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member

Abstract

An electric oil pump 1 according to the present invention is provided with: an oil pump unit 2 which comprises a pump rotor 8 and a pump housing 10 that contains the pump rotor 8; a motor unit 3 which comprises a motor rotor 16, a motor stator 17, and a motor housing 18 that contains the motor rotor 16 and the motor stator 17; a control unit 4 which controls the driving of the motor unit 3; and first and second bearings 27, 28 that support rotary shafts 5, 6, which protrude from the motor rotor 16 in the axial direction, at two points in the axial direction. The pump housing 10 and the motor housing 18 are integrally formed; and both of the first and second bearings 27, 28 are needle roller bearings.

Description

Electric oil pump

The present invention relates to an electric oil pump.

In recent years, electrification for the purpose of labor saving and low fuel consumption of vehicles, etc. has progressed. For example, a system for operating the transmission, brake, steering, etc. of an automobile with the power of an electric motor such as a motor has been developed and put on the market. Has been. In addition, hydraulic drive devices such as oil pumps are also becoming electrified. For example, an electric oil pump that drives an oil pump with a motor is adopted and put into practical use for the purpose of supplying hydraulic pressure to a transmission when an automobile engine is idling. Has reached.

In addition, regarding this type of electric oil pump, there is an increasing demand for miniaturization in view of the fact that it must be installed in a limited space of the vehicle body. Therefore, recently, an electric oil pump in which an oil pump and a motor, and further a motor controller are integrated (unitized) has been proposed. In this case, the rotor of the oil pump is fixed to the rotating shaft of the motor, and the rotating shaft is supported by two bearings. In addition, one of the two bearings is fixed to the pump cover, and the other bearing is fixed to the pump housing. The pump housing is formed separately from the motor housing. A motor stator is fixed to the motor housing (see, for example, Patent Document 1).

Japanese Patent No. 6056149

As described above, when the rotor of the oil pump is driven to rotate by the motor, the performance of the oil pump is affected by the rotation accuracy of the motor. Further, the rotational accuracy of the motor is affected by the assembly accuracy of the motor stator and the bearing that supports the rotating shaft that rotates integrally with the motor rotor. Therefore, as in Patent Document 1, the motor housing to which the motor stator is fixed is attached to the pump housing, and the pump cover to which the bearing is fixed is attached to the pump housing. There is a possibility that required assembling accuracy cannot be secured between the motor stator and the bearing.

In view of the above circumstances, in the present specification, it is a technical problem to be solved to improve the performance of the oil pump by increasing the motor assembly accuracy while reducing the size of the electric oil pump.

The solution of the technical problem is achieved by the electric oil pump according to the present invention. That is, this pump includes a pump rotor, an oil pump portion having a pump housing that houses the pump rotor, a motor portion having a motor rotor and a motor stator, and a motor housing that houses the motor rotor and the motor stator, and a motor portion. An electric oil pump comprising a control unit that controls the driving of the motor and a first and second bearing that supports a rotating shaft that protrudes in the axial direction from the motor rotor at two locations in the axial direction. It is characterized in that it is integrally formed and both the first and second bearings are needle roller bearings. The integral formation here includes not only the case where the pump housing and the motor housing are integrally formed of the same material, but also the case where, for example, one housing is used as an insert and the other housing is molded. It is.

As described above, according to the present invention, since the pump housing and the motor housing are integrally formed, elements (bolts, seal members, etc.) for fixing the housings to each other can be omitted, and the electric oil pump is lightened accordingly. And it can be made compact. Further, by using both the first and second bearings that support the rotating shaft as needle roller bearings, the load capacity in the radial direction can be made larger than that of a sliding bearing such as a bush. In addition, since the load capacity and bearing rigidity in the same space can be increased compared to ball bearings, the bearing installation space can be reduced while ensuring the same load capacity and bearing rigidity as before. This can also reduce the size of the electric oil pump.

Also, by integrally forming the pump housing and the motor housing, the accumulation of assembly tolerances between the housings, cases, and covers is eliminated or reduced. Therefore, for example, even when the first bearing is fixed to the pump cover attached to the motor housing via the pump housing, sufficient assembly accuracy can be ensured between the bearing and the motor stator. Therefore, it is possible to improve the rotation accuracy of the motor unit that rotationally drives the rotation shaft supported by the bearing, thereby improving the rotation accuracy of the pump rotor, and hence the pump performance.

Further, in the electric oil pump according to the present invention, the rotation shaft protrudes from the motor rotor on both sides in the axial direction, the tip end portion of the first rotation shaft protruding in one axial direction is supported by the first bearing, and the axial direction The tip of the second rotating shaft protruding to the other side may be supported by the second bearing. *

In the electric oil pump, a radial load acts on the pump rotor during oil suction and discharge. Since the pump rotor is connected to the rotation shaft of the motor unit, when a radial load is applied to the pump rotor, a force is applied to the rotation shaft of the motor unit in a direction in which the rotation shaft is inclined. If the rotation shaft is inclined, the pump rotor may be inclined and the pump performance may be deteriorated. Therefore, the rotation shaft is required to have not only high rotation accuracy but also high bearing rigidity. Here, in the present invention, as described above, the tip end portion of the first rotating shaft that protrudes from the motor rotor to the one side in the axial direction is supported by the first bearing, and the second portion that protrudes from the motor rotor to the other side in the axial direction. It was set as the form which each supported the front-end | tip part of the rotating shaft with the 2nd bearing. By comprising in this way, the rotating shaft containing a motor rotor can be supported by the largest bearing span. Therefore, according to this bearing arrangement, it is possible to give the motor and the pump rotor high rotational accuracy by suppressing the inclination of the rotating shaft to the maximum.

Also, in this case, in the electric oil pump according to the present invention, the control unit has a substrate and a case for housing the substrate, the case is attached to the motor housing, and the oil pump unit is attached to the pump housing. A pump cover may be further provided, the first bearing may be fixed to the pump cover, and the second bearing may be fixed to the case.

By attaching the control unit case to the motor housing and fixing the bearings to the pump cover and the control unit case, the first, second, and second shapes are not complicated. The axial span of the bearing can be maximized. Therefore, it is possible to realize the maximum bearing rigidity relatively easily. Of course, since both the case of the control unit and the pump cover are attached to the integrally formed motor housing and pump housing, accumulation of assembly tolerances can be minimized. Therefore, there is no problem in terms of assembly accuracy.

Further, in the electric oil pump according to the present invention, the oil circulation space including the internal space of the pump housing and the oil flowing therethrough and the internal space of the motor housing are partitioned by a seal portion, and both the first and second bearings are oil It may be disposed in the distribution space.

For example, when the bearing is disposed in the internal space of the motor housing, a space for retaining lubricating oil or grease is required inside the bearing in order to smoothly and long-term lubricate the oil. Further, it is necessary to attach a seal mechanism for preventing oil leakage to the outside of the bearing at the end portion in the axial direction of the bearing. On the other hand, as described above, by arranging the first and second bearings in the oil circulation space including the internal space of the pump housing, the bearings can be lubricated with the oil circulating in the pump. Become. Therefore, the space for sealing the lubricating oil or grease can be omitted, and the bearing can be further downsized. Further, the size of the bearing can be reduced by omitting the seal mechanism. Further, according to the above configuration, since it is not necessary to provide a bearing in the internal space of the motor housing or the internal space of the control unit case, the degree of freedom in designing the motor housing and the control unit case is increased. Therefore, it is possible to simplify the housing and the case and further reduce the size.

In the electric oil pump according to the present invention, the motor rotor has a sleeve portion and a shaft portion that is fitted and fixed to the inner periphery of the sleeve portion, and the shaft portion protrudes in the axial direction from the sleeve portion and has a rotating shaft. You may comprise.

The motor unit has a motor rotor and a rotating shaft protruding in the axial direction from the motor rotor. In this case, required physical properties, surface properties, and the like are different between the motor rotor and the rotating shaft. Therefore, by manufacturing the rotating shaft and the motor rotor (particularly the large-diameter side facing the stator) separately and integrating them later, it is possible to reduce the processing cost while satisfying the required characteristics of each part. Become. Further, if the shaft portion and the sleeve portion are manufactured separately as in the present invention, the shape of each member can be simplified, and this also makes it possible to keep the processing cost low.

Further, in this case, in the electric oil pump according to the present invention, the end of the shaft portion opposite to the pump portion is retracted to the pump portion side from the end of the sleeve portion opposite to the pump portion, and the shaft A sensor target (for example, a sensor magnet) is disposed adjacent to the end of the unit opposite to the pump unit in the axial direction, and phase information of the sensor target is detected at a position facing the sensor target in the axial direction. A sensor may be provided.

Thus, by providing the sensor target on the motor rotor side and providing the sensor that detects the phase information of the sensor target at a position facing the sensor target in the axial direction, the rotational phase and rotational speed of the rotating shaft can be acquired. . Therefore, by controlling the driving of the motor unit based on the acquired information, it becomes possible to control the driving of the pump unit with higher accuracy. Further, if the sensor target is disposed in the space provided on the inner periphery of the sleeve portion by shifting the end portion of the shaft portion toward the pump portion side, it is not necessary to newly provide a dedicated space for arranging the sensor target. Therefore, there is no possibility of hindering the miniaturization of the electric oil pump.

As described above, according to the present invention, it is possible to improve the rotation accuracy of the pump by increasing the motor assembly accuracy while reducing the size of the electric oil pump.

It is sectional drawing of the electric oil pump which concerns on 1st embodiment of this invention. It is an exploded view of the electric oil pump shown in FIG. It is sectional drawing of the electric oil pump which concerns on 2nd embodiment of this invention. It is sectional drawing of the electric oil pump which concerns on 3rd embodiment of this invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. In the drawings for explaining the present invention, components such as members and components having the same function or shape are denoted by the same reference numerals as much as possible, and once described, the description will be given. Omitted.

<First embodiment of the present invention>
FIG. 1 is a cross-sectional view of the electric oil pump according to the first embodiment of the present invention, and FIG. 2 is an exploded view of the electric oil pump shown in FIG.

As shown in FIG. 1, an electric oil pump 1 according to this embodiment includes a pump unit 2, a motor unit 3 that rotationally drives a pump rotor of the pump unit 2, and a control unit 4 that controls driving of the motor unit 3. The bearing part 7 which supports the rotating shafts 5 and 6 of the motor part 3 is provided. Details of each element will be described below.

The pump unit 2 is a positive displacement oil pump, and in the present embodiment, as shown in FIGS. 1 and 2, a so-called trochoid oil pump is configured. That is, the pump portion 2 includes an inner gear 8 and an outer gear 9 that have different numbers of teeth and mesh with each other, a pump housing 10 that houses the inner gear 8 and the outer gear 9, and a pump cover 11 that closes the opening 10a of the pump housing 10. Have Here, the inner gear 8 corresponds to the pump rotor according to the present invention. The pump cover 11 is fixed to the pump housing 10 via a seal member 12 such as an O-ring, for example, in contact with the opening-side end surface 10 b of the pump housing 10.

In this embodiment, the pump cover 11 has an inlay portion 13 that protrudes toward the pump housing 10 and fits into the opening portion 10a. The inlay portion 13 is fitted into the opening portion 10a, and a bolt 14 is used. By fastening the pump cover 11 to the pump housing 10, the pump cover 11 is fixed to the pump housing 10 with radial positioning. The pump cover 11 is made of a metal such as aluminum, an aluminum alloy, or an iron-based metal such as stainless steel. The material of the pump housing 10 will be described later.

The motor unit 3 includes a motor rotor 16 and a motor stator 17 that are opposed to each other in the radial direction, and a motor housing 18.

The motor stator 17 has a stator core 19, bobbins 20 attached to both axial ends of the stator core 19, and a coil 21 wound around the bobbin 20.

The motor housing 18 has a bottomed cylindrical portion (see FIG. 2) and houses the motor rotor 16 and the motor stator 17. The controller 4 is attached to the opening 18 a of the motor housing 18, thereby closing the internal space of the motor housing 18. A stator core 19 of the motor stator 17 is fixed to the large-diameter inner peripheral surface 18 b of the motor housing 18. A small-diameter inner peripheral surface 18c that is smaller in diameter than the large-diameter inner peripheral surface 18b is formed on the side closer to the pump portion 2 than the large-diameter inner peripheral surface 18b, and the small-diameter inner peripheral surface 18c has a seal. A member 22 is attached.

The motor housing 18 configured as described above is formed integrally with the pump housing 10. In the present embodiment, the openings 10a and 18a that are opened in opposite directions are integrated with each other. The integrated product of the motor housing 18 and the pump housing 10 is obtained, for example, by forming the motor housing 18 and the pump housing 10 with the same material (for example, metal). Here, for example, the motor housing 18 and the pump housing 10 can be integrally formed by casting aluminum or an aluminum alloy. Of course, the motor housing 18 and the pump housing 10 may be integrally formed of a metal other than the above (for example, a sintered metal body of an iron-based metal such as stainless steel).

The motor rotor 16 has a cylindrical shape as a whole (see FIG. 2), and includes a rotor core 23 and a rotor magnet 24 attached to the outer periphery of the rotor core 23. Further, rotary shafts 5 and 6 are provided on both axial sides of the motor rotor 16 so that the motor rotor 16 and the rotary shafts 5 and 6 rotate coaxially.

In the present embodiment, the motor rotor 16 includes a sleeve portion 25 and a shaft portion 26 that is fitted and fixed to the inner periphery of the sleeve portion 25. The shaft portion 26 protrudes from the sleeve portion 25 on both sides in the axial direction, and these protruding portions constitute the rotating shafts 5 and 6. At this time, the shaft portion 26 can be formed of an arbitrary material. However, as shown in FIG. 1, when the outer peripheral surface of the shaft portion 26 constitutes inner raceway surfaces of bearings 27 and 28 described later. The same material as the rolling elements of the bearings 27 and 28 is preferable, and the surface layer portion including the surface of the shaft portion 26 is adjusted to a predetermined hardness by quenching or the like.

The control unit 4 includes a substrate 29 and a case 30 that accommodates the substrate 29. Here, the case 30 includes a case main body 31 and a case cover 32. In the present embodiment, the case main body 31 is fixed to the motor housing 18 via a seal member 33 such as an O-ring, and the substrate 29 is installed on the opposite side of the case main body 31 from the motor unit 3. The substrate 29 is electrically connected to the motor stator 17 by a bus bar 34 (see FIG. 2) extending from the motor stator 17. In addition, the case cover 32 is provided with a coupler 35, which enables power supply to the substrate 29 and further to the motor stator 17 from an external power source (not shown). Although illustration is omitted, the case cover 32 may be provided with a heat sink for promoting heat dissipation of the substrate 29. The case cover 32 is fixed to the motor housing 18 with bolts 36 in a state (for example, a state shown in FIG. 2) that is temporarily fixed to the case body 31 by adhesion or the like in advance. Of course, the means for fixing the case cover 32 to the case body 31 is arbitrary, and various means other than those described above can be adopted. Similarly, the means for fixing the case 30 to the motor housing 18 is also optional.

The bearing portion 7 is composed of two bearings 27 and 28. In the present embodiment, the first rotating shaft 5 that protrudes from the motor rotor 16 to one side in the axial direction (the pump unit 2 side) is supported by the first bearing 27. Further, the second rotating shaft 6 protruding from the motor rotor 16 to the other axial side (the control unit 4 side) is supported by the second bearing 28.

The first bearing 27 is fixed by, for example, press-fitting to a concave bearing mounting portion 37 provided on the inner end surface 11 a of the pump cover 11, and the second bearing 28 is fixed to the case main body 31 of the case 30 of the control unit 4. For example, it is fixed by press fitting to the concave bearing mounting portion 38 provided. At this time, the first bearing 27 is fixed to the bearing mounting portion 37 via a collar 39 made of metal (for example, various types of ferrous metals including cold rolled steel plate, stainless steel, and carbon steel), The bearing 28 is also fixed to the bearing mounting portion 38 via a metal collar 40.

Here, both the bearings 27 and 28 used are needle roller bearings. In the present embodiment, the bearings 27 and 28 include a plurality of needle rollers 27a and 28a, cages 27b and 28b that hold these needle rollers 27a and 28a, and outer raceway surfaces of the needle rollers 27a and 28a. And outer rings 27c and 28c having an inner circumference. In this case, the inner circumferential side raceways of the needle rollers 27 a and 28 a are constituted by the outer circumferential surface of the shaft portion 26.

The electric oil pump 1 having the above configuration is assembled, for example, through the following procedure. First, as shown in FIG. 2, the shaft portion 26 is fitted and fixed to the inner periphery of the sleeve portion 25, thereby manufacturing the motor rotor 16 in which the rotary shafts 5 and 6 protrude on both sides in the axial direction. Further, the first bearing 27 is fixed to the bearing mounting portion 37 of the pump cover 11 with the collar 39 interposed, and the second bearing 28 is fixed to the case main body 31 of the control unit 4 with the collar 40 interposed. It fixes to the bearing attachment part 38 of this. Then, the motor rotor 16 is introduced into the motor housing 18 from the opening 18a side, and the first rotation shaft is inserted into the through hole 42 (see FIG. 1) provided in the integral portion 41 of the pump housing 10 and the motor housing 18. By inserting 5, the distal end side of the first rotating shaft 5 reaches the inside of the pump housing 10. Thereafter, the inner gear 8 is fitted and fixed to the front end side of the first rotating shaft 5 by press fitting, for example, and the pump cover 11 is fixed to the pump housing 10 with the outer gear 9 fitted to the outer periphery of the inner gear 8. . As a result, the tip of the first rotary shaft 5 is introduced into the inner periphery of the first bearing 27 provided on the pump cover 11, and the first rotary shaft 5 is supported by the first bearing 27.

Next, as shown in FIG. 2, the control unit 4 prepared in advance is fixed to the opening 18 a of the motor housing 18 by housing the substrate 29 and the like and fixing the case cover 32 to the case main body 31. . At this time, since the second bearing 28 is fixed to the case main body 31, the second protrusion 28 protrudes from the motor rotor 16 to the control section 4 side by fixing the control section 4 (case main body 31) to the motor housing 18. The tip of the rotary shaft 6 is introduced into the inner periphery of the second bearing 28 provided in the case body 31, and the second rotary shaft 6 is supported by the second bearing 28.

Thus, when the pump unit 2, the motor unit 3, and the control unit 4 are assembled to each other, the internal space of the control unit 4 (the internal space of the case 30) is sealed. Further, the seal member 22 attached to the inner periphery of the motor housing 18 is in a state in which the seal member 22 can be slidably contacted with the first rotary shaft 5, so And a space formed between the inner gear 8 and the outer gear 9), a space between the through hole 42 and the first rotating shaft 5, and an internal space of the motor unit 3 are partitioned by the seal member 22. It becomes a state. At this time, the internal space of the pump portion 2 and the space communicating with the pump portion 2 function as the oil circulation space 43.

As described above, according to the electric oil pump 1 according to the present invention, since the pump housing 10 and the motor housing 18 are integrally formed, elements (bolts and seals) for mutually fixing the housings 10 and 18 together. Member etc. can be omitted, and the electric oil pump 1 can be made lighter and more compact accordingly. In addition, since both the first and second bearings 27 and 28 that support the rotary shafts 5 and 6 are needle roller bearings, the load capacity in the radial direction can be made larger than that of a sliding bearing such as a bush. . In addition, since the load capacity and bearing rigidity in the same space can be increased as compared with ball bearings, the installation space for the bearings 27 and 28 can be reduced while ensuring the same load capacity and bearing rigidity as in the past. Accordingly, the electric oil pump 1 can be reduced in size.

Further, by integrally forming the pump housing 10 and the motor housing 18, the accumulation of assembly tolerances between the housings 10, 18 and the case 30, and the pump cover 11 is eliminated or reduced. Therefore, for example, when the first bearing 27 is fixed to the pump cover 11 attached to the motor housing 18 via the pump housing 10 as in the embodiment, the insole shown in FIG. By positioning the pump cover 11 in the radial direction, sufficient assembly accuracy can be ensured between the bearing 27 and the motor stator 17 fixed to the motor housing 18. The second bearing 28 is fixed to the case main body 31 of the case 30, and the case main body 31 is directly fixed to the motor housing 18. Therefore, the rotational accuracy of the motor unit 3 that rotationally drives the rotary shafts 5 and 6 supported by the bearings 27 and 28 can be increased, whereby the rotational accuracy of the pump rotor (inner gear 8), and thus the performance of the pump unit 2 can be improved. Can be improved.

In the present embodiment, the first bearing 27 is fixed to the pump cover 11 far from the motor unit 3 toward the pump unit 2, and the second bearing 28 is secured from the motor unit 3 to the control unit 4 side. Fixed to the main body 31. By arranging both the bearings 27 and 28 in this way, the axial span of the bearings 27 and 28 is maximized to support the first rotary shaft 5 at its tip, and the second rotation. It becomes possible to support the shaft 6 at its tip. Thereby, it becomes possible to give the motor part 3 and the pump rotor (inner gear 8) high rotational accuracy by suppressing the inclination of the rotary shafts 5 and 6 to the maximum.

Further, in the present embodiment, as shown in FIG. 1, a through hole 42 is provided in the integral part 41 of the pump housing 10 and the motor housing 18, the first rotary shaft 5 is inserted, and the inner end face ( The end face in the axial direction of the inner gear 8 can be brought into contact with almost the entire surface of the end face 10c where the through hole 42 is open on the pump part 2 side. Thus, by disposing the inner end surface 10c of the pump housing 10 so as to face the axial end surface of the inner gear 8, tilting of the inner gear 8 can be restricted by the inner end surface 10c. Therefore, also by this, it becomes possible to suppress the inclination of the rotating shafts 5 and 6 to the maximum, and to impart high rotational accuracy to the motor unit 3 and the pump rotor (inner gear 8).

Although one embodiment (first embodiment) of the electric oil pump according to the present invention has been described above, this electric oil pump can naturally take any form within the scope of the present invention. *

<Second embodiment of the present invention>
FIG. 3 shows a cross-sectional view of the electric oil pump 51 according to the second embodiment of the present invention. The electric oil pump 51 according to the present embodiment is different from the electric oil pump 1 according to the first embodiment in that the second bearing 28 is mainly fixed at a position close to the pump portion 2. Specifically, a through-hole 42 provided in the integral part 41 of the pump housing 10 and the motor housing 18 is partially enlarged to form a bearing mounting part 52, and the second bearing 28 is attached to the bearing mounting part 52. It is fixed. In this case, the seal member 22 is adjacent to the motor unit 3 side of the second bearing 28. Therefore, when the electric oil pump 51 is assembled as shown in FIG. 3, the first bearing 27 and the second bearing 28 are both disposed in the oil circulation space 43 including the internal space of the pump unit 2. It becomes.

In this way, by arranging the first and second bearings 27 and 28 in the oil circulation space 43 including the internal space of the pump portion 2, the oil circulating (circulating) in the internal space of the pump portion 2 is used. The bearings 27 and 28 can be lubricated. Therefore, a space for sealing the lubricating oil or grease becomes unnecessary, and the bearings 27 and 28 can be further downsized. Further, since it is not necessary to provide the second bearing 28 with a seal mechanism for preventing leakage, the second bearing 28 can be downsized. Further, if the seal mechanism can be omitted, the sliding resistance between the bearings 27 and 28 and the first rotating shaft 5 is reduced, so that the loss torque of the motor unit 3 is suppressed and energy saving is achieved while suppressing the predetermined pump performance. It becomes possible to demonstrate. At this time, since the first bearing 27 and the second bearing 28 are arranged adjacent to both sides in the axial direction of the inner gear 8, the axial span of the bearings 27 and 28 is the same as that in the first embodiment. Even if it becomes shorter than that, there is no particular problem in terms of the ability to prevent the tilt of the first rotating shaft 5 (the bearings 27 and 28 have sufficient ability to prevent tilting). *

Further, according to the above configuration, it is not necessary to provide the second bearing 28 in the internal space of the motor housing 18 or the internal space of the case 30 of the control unit 4. Design flexibility increases. Therefore, the motor housing 18 and the case 30 can be simplified and further miniaturization can be achieved. Specifically, the bearing mounting portion 38 is omitted, and the rear end portion (end portion on the control unit 4 side) 26a of the shaft portion 26 is moved backward from the rear end portion 25a of the sleeve portion 25 toward the pump portion 2 side. Thus, the shape of the case main body 53 can be brought close to a simple plate shape (see FIG. 3). Further, by omitting the bearing mounting portion 38, a space corresponding to the omitted space is generated between the case main body 31 and the case cover 32. For example, the degree of freedom in arrangement of the bus bars 34 can be increased.

<Third embodiment of the present invention>
FIG. 4 shows a cross-sectional view of an electric oil pump 61 according to the third embodiment of the present invention. The electric oil pump 61 according to the present embodiment is mainly configured to be able to detect the phase information of the first rotating shaft 5, and the electric oil pumps 1, 51 according to the first and second embodiments are It is different. Specifically, the sensor target 62 is arranged in a space formed on the inner periphery of the sleeve portion 25 by retreating the rear end portion 26a of the shaft portion 26 to the pump portion 2 side with respect to the rear end portion 25a of the sleeve portion 25. The sensor 63 is disposed at a position facing the sensor target 62 in the axial direction. In the present embodiment, the sensor target 62 is a sensor magnet. The sensor 63 is attached to the substrate 29. Further, the case main body 64 existing between the sensor target 62 and the sensor 63 is provided with an axial through hole 65 so that the facing distance between the sensor target 62 and the sensor 63 is reduced.

Here, any kind of sensor target 62 and sensor 63 can be applied as long as information related to phase information such as phase information or rotational speed of the first rotating shaft 5 can be detected. A type of sensor target and sensor capable of detecting appropriate phase information in accordance with control may be employed.

Thus, according to the electric oil pump 61 according to the present embodiment, the rotational phase or rotational speed of the first rotary shaft 5 can be acquired. Therefore, for example, by sending the acquired information to the substrate 29 to which the sensor 63 is attached and controlling the drive of the motor unit 3 based on the acquired information, more accurate drive control of the pump unit 2 is achieved. It becomes possible. Further, if the sensor target 62 is disposed in the space provided on the inner periphery of the sleeve portion 25 by retracting the rear end portion 26a of the shaft portion 26 toward the pump portion 2, the dedicated portion for arranging the sensor target 62 is provided. Since it is not necessary to provide a new space, there is no possibility of preventing the electric oil pump 1 from being downsized.

In addition, in this embodiment, although the opposing distance of the sensor target 62 and the sensor 63 is reduced and the case where the through-hole 65 is provided from a viewpoint of the moldability (workability) of the case main body 64 is illustrated, Of course, this need not be the only case. For example, from the viewpoint of reliably preventing foreign matter from flowing from the motor unit 3 side to the control unit 4 side, the case body 64 is formed of a material that does not affect the detection of phase information from a sensor target such as resin, and the through hole 65 is formed. It may be omitted and the case main body 64 may be interposed between the sensor target 62 and the sensor 63.

In addition, although the case where the 1st bearing 27 was fixed to the pump cover 11 was illustrated in the above embodiment, of course, the 1st and 2nd bearings 27 and 28 can also take other arrangement forms. . For example, although not shown, the first bearing 27 may be fixed to the bearing mounting portion 52 shown in FIG. 3 or the like, and the second bearing 28 may be fixed to the bearing mounting portion 38 shown in FIG. Alternatively, although not shown, a bearing mounting portion is provided at a position adjacent to the seal member 22 on the control unit 4 side on the inner peripheral surface of the motor housing 18, and the first bearing 27 is provided on the bearing mounting portion. The arrangement may be such that the second bearing 28 is fixed to the bearing mounting portion 38 by being fixed. In short, as long as both the first and second bearings 27 and 28 are needle roller bearings, the arrangement can be arbitrarily set.

Further, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be implemented in various forms without departing from the gist of the present invention. , And includes all equivalents to the equivalent meanings recited in the claims and within the scope of the claims.

Claims (6)

  1. An oil pump portion having a pump rotor and a pump housing for accommodating the pump rotor;
    A motor portion having a motor rotor and a motor stator, and a motor housing that houses the motor rotor and the motor stator;
    A control unit for controlling the driving of the motor unit;
    In the electric oil pump comprising the first and second bearings supporting the rotating shaft protruding in the axial direction from the motor rotor at two locations in the axial direction,
    The electric oil pump, wherein the pump housing and the motor housing are integrally formed, and the first and second bearings are both needle roller bearings.
  2. The rotating shaft protrudes from the motor rotor on both sides in the axial direction, and a tip end portion of the first rotating shaft that protrudes on one side in the axial direction is supported by the first bearing and protrudes on the other side in the axial direction. The electric oil pump according to claim 1, wherein the tip end of the second rotating shaft is supported by the second bearing.
  3. The control unit includes a substrate and a case for housing the substrate, the case is attached to the motor housing, and the oil pump unit further includes a pump cover attached to the pump housing,
    The electric oil pump according to claim 2, wherein the first bearing is fixed to the pump cover, and the second bearing is fixed to the case.
  4. An oil circulation space in which oil flows including the internal space of the pump housing and an internal space of the motor housing are partitioned by a seal portion
    The electric oil pump according to claim 1, wherein both the first and second bearings are disposed in the oil circulation space.
  5. The motor rotor has a sleeve portion and a shaft portion that is fitted and fixed to the inner periphery of the sleeve portion,
    The electric oil pump according to any one of claims 1 to 4, wherein the shaft portion protrudes in an axial direction from the sleeve portion to constitute the rotating shaft.
  6. The end portion of the shaft portion opposite to the pump portion is retracted to the pump portion side from the end portion of the sleeve portion opposite to the pump portion,
    A sensor for detecting phase information of the sensor target at a position where a sensor target is disposed adjacent to the end of the shaft portion opposite to the pump portion in the axial direction and opposed to the sensor target in the axial direction. The electric oil pump according to claim 5, wherein
PCT/JP2019/019263 2018-05-21 2019-05-15 Electric oil pump WO2019225425A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2018097094A JP2019203390A (en) 2018-05-21 2018-05-21 Motor oil pump
JP2018-097094 2018-05-21

Publications (1)

Publication Number Publication Date
WO2019225425A1 true WO2019225425A1 (en) 2019-11-28

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Application Number Title Priority Date Filing Date
PCT/JP2019/019263 WO2019225425A1 (en) 2018-05-21 2019-05-15 Electric oil pump

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JP (1) JP2019203390A (en)
WO (1) WO2019225425A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007292005A (en) * 2006-04-27 2007-11-08 Hitachi Ltd Pump device and power steering device
JP2013064395A (en) * 2011-08-31 2013-04-11 Jtekt Corp Electric pump unit
JP2014122629A (en) * 2012-12-21 2014-07-03 Lg Innotek Co Ltd Electric pump
JP2015163029A (en) * 2014-02-28 2015-09-07 アイシン精機株式会社 Shaft structure of electric oil pump
JP2017123731A (en) * 2016-01-07 2017-07-13 日本電産サンキョー株式会社 motor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007292005A (en) * 2006-04-27 2007-11-08 Hitachi Ltd Pump device and power steering device
JP2013064395A (en) * 2011-08-31 2013-04-11 Jtekt Corp Electric pump unit
JP2014122629A (en) * 2012-12-21 2014-07-03 Lg Innotek Co Ltd Electric pump
JP2015163029A (en) * 2014-02-28 2015-09-07 アイシン精機株式会社 Shaft structure of electric oil pump
JP2017123731A (en) * 2016-01-07 2017-07-13 日本電産サンキョー株式会社 motor

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